Lawn & Garden Tools
Seed, water, feed and mow — with the rates and the timing that decide whether any of it works.
Seed quantities for a new lawn or an overseed, with the sod alternative — and why a pound of one grass is ten pounds of another.
Sprinkler Run Time CalculatorHow long to run each zone for an inch of water — and why a spray head on clay wastes most of it after six minutes.
Lawn Fertilizer Nitrogen CalculatorHow much of the bag to spread for a pound of actual nitrogen — and why a "balanced" 10-10-10 is really 1 : 0.44 : 0.83.
Sprinkler Zone & Pipe Size PlannerHow many heads fit on a zone, what pipe carries them, and why a rotor in a corner waters four times as fast as one in the open.
Mowing Height & Frequency CalculatorThe one-third rule as arithmetic — when to mow, how many cuts an overgrown lawn needs, and why cutting shorter means mowing more often.
Pre-Emergent Timing CalculatorWhen to apply crabgrass pre-emergent, why an afternoon soil reading is 6.5 degrees high, and why going early loses the back of the window.
Mulch, Topsoil & Gravel CalculatorYards, tons and bags for any bulk landscape material — plus why a ton of mulch is four times a ton of stone, and when bags beat delivery.
Lawn Aeration & Dethatching PlannerHow many aerator passes you actually need, whether the thatch wants removing, and the order the jobs go in.
Soil Test & Lime / Sulfur CalculatorHow much lime or sulfur a pH change really needs — and why soil texture decides the amount far more than the pH reading does.
Grass Type PickerWhich lawn grass suits your climate, shade, traffic and patience — with the ones your climate rules out listed separately, and why.
Yard Drainage & Grading PlannerHow much water your roof and yard actually shed, whether the grade survives settlement, and what a French drain can really hold.
Tree Planting & Spacing PlannerSpacing, setbacks, root zone and planting hole for a tree at maturity — and why correct spacing looks 99 per cent empty on the day.
Sprayer Calibration CalculatorWhat your sprayer actually puts down, using the 1/128 acre method — which is exact rather than a rule of thumb, and here is why.
Lawn Weed Identification KeyIdentify 28 common lawn weeds from what you can see — and find out what each one is telling you about the lawn.
Landscape Lighting Transformer SizingTransformer size, voltage drop and layout for low-voltage lighting — and why 12 volts loses 100 times more of its supply than 120 does.
Xeriscape Water Savings CalculatorWhat a xeriscape conversion really saves, computed from the irrigation model — and why the two levers multiply rather than add.
Farmer's Planting CalendarPlanting dates come from your frost dates, not the calendar. The last frost spans four months across zones, so "plant in May" is a guess.
About these lawn & garden tools
Almost everything that goes wrong with a lawn is a timing problem wearing a quantity problem’s clothes. Sow cool-season grass in spring and the seedlings get roughly ten weeks of root growth before summer heat arrives; sow the same seed in early autumn and they get the best part of a year before meeting their first summer. The rate on the bag is the thing people measure carefully and the season is the thing that decides the outcome, which is an awkward combination for anyone who likes calculators. The same pattern runs through watering — a lawn watered lightly every day grows roots in the top inch of soil and then dies the first week nobody waters it, where the same total water delivered once or twice a week drives roots deep enough to survive being forgotten. Where quantity does matter, it is usually not the quantity people think. A seeding rate is a seed count wearing a weight label: Kentucky bluegrass carries about 2,200,000 seeds to the pound and tall fescue about 227,000, a factor of ten, which is the entire reason one is sown at two and a half pounds per thousand square feet and the other at eight. Comparing two seeding rates by weight compares nothing at all. Fertiliser has the same structure — the useful figure is pounds of nitrogen per thousand square feet, not pounds of product, and a bag at 30 per cent nitrogen delivers three times what a 10 per cent bag does at the same spreader setting. And mowing has a rule that survives every other disagreement about lawns: never remove more than a third of the blade at once. A grass plant cut harder than that stops growing roots while it rebuilds leaf, which is why a neglected lawn scalped back into shape takes months to recover and a lawn cut often at the same height never needs to. Most of these tools are about getting a number right; the ones worth reading twice are about getting the week right.